A lighting unit may be implemented using a plurality of different colored light sources such as different colored light emitting diodes (LEDs). For example, a lighting unit may include a white LED, a red LED, a blue LED and a green LED. Because of manufacturing process variations, the color emitted by a particular LED may differ from its intended or nominal color. For example, blue LEDs may not all emit the same color or intensity of blue light. Accordingly, different lighting units may emit different colors of light given the same control inputs. For example, when controlled to emit green light, a first lighting unit may emit a blue-tinted green light, while another lighting unit may emit a red-tinted green light. When a plurality of such lighting units is combined to light a space such as an airplane cabin, the color of light emitted throughout the cabin may display unacceptable variation in color or intensity.
Conventional solutions to overcome these problems include the screening of light sources (e.g., LEDs) to reduce variability in emitted light color to acceptable tolerances. However, such screening may result in unacceptable costs and/or manufacturing yields. Another conventional solution calibrates lighting units to achieve color consistency for a small number of fixed colors of light. However, such conventional calibration methods prevent multi-colored lighting units from being used to their fullest potential, and prevent users from creating customized lighting conditions.